ST. LOUIS (AP) – A select group of sergeants will be the first St. Louis police officers to try out body cameras.

St. Louis police Chief Sam Dotson says he expects 90 of the department’s roughly 200 sergeants to try out the body cameras in a pilot program starting Monday.

The St. Louis Post-Dispatch reports (http://bit.ly/1OQXRzs ) that the union contract protects officers from having to wear body cameras until the issue goes through a formal process.

Sergeants who are exempt from the union contract will be wearing them for 30 days at a time before handing them off to other sergeants.

Dotson says he plans to negotiate with the police union while testing the cameras.

The union’s business manager says paying officers better, providing more training and boosting morale would do more to improve the department than installing body cameras.